/Engine/Source/Runtime/MeshDescription/Public/MeshDescriptionBase.h
Returns the adjacent triangles to this triangle
void GetTriangleAdjacentTriangles ( [FTriangleID](API\Runtime\MeshDescription\FTriangleID) TriangleID, [TArray](API\Runtime\Core\Containers\TArray)< [FTriangleID](API\Runtime\MeshDescription\FTriangleID) > & OutTriangleIDs ) const